E = mc^2

Einstein's famous equation indirectly describes the origin of energy (E). To make a long story short, energy (E) is created in nuclear reactions when matter/mass (m) is converted directly into heat, light, or other forms of electromagnetic energy.

There are two fundamental types of nuclear reactions that change matter/mass (m) into energy (E): fission reactions in which the nuclei of Uranium or Plutonium atoms are split into smaller nuclei, and fusion reactions in which smaller atoms (like hydrogen) are squeezed together forming larger atoms (like helium).

Now you can understand why our Sun is losing five million tons of mass per second: fusion reactions deep within the core are changing matter/mass (m) into energy (E): the heat and light that we see and feel. A look up into a clear night sky reveals thousands of gigantic nuclear fusion reactors, twinkling as they change matter/mass (m) into energy (E).

You can also understand how nuclear reactors in power plants produce heat for boiling water without burning any fossil fuels: carefully controlled fission reactions convert some of the sub-atomic matter in Uranium or Plutonium atoms directly into heat.

Nuclear weapons also use fission or fusion to produce an instantaneous chain reaction that converts some of the matter in the bomb into the heat (and light) of an atomic or thermonuclear bomb blast. "Little Boy", the first atomic bomb ever used, was dropped over Hiroshima, Japan on August 6, 1945 during WW II. It contained 64 kilograms of Uranium atoms; after detonation, 63 kilograms of smaller atoms remained. Yes, a mere one kilogram of matter (2.2 lbs.) was converted into enough energy to destroy a large city and kill tens of thousands of Japanese.

Looking at Einstein's equation you are hopefully wondering why he included, "c squared".

In physics, "c" denotes the speed of light which is a very large number; when a very large number is squared (multiplied by itself), it results in a very enormous number. By including this in the equation (E = mc^2), Einstein mathematically explained the relationship between the amount of matter/mass (m) and the amount of energy (E) it is changed into. Based on what you now know, which of the following accurately describes this relationship in nuclear reactions:

A) A small amount of matter changes into a large amount of energy.

B) A large amount of matter changes into a small amount of energy.

C) Amounts of converted matter and energy created are equivalent

The answer is below:

A